1. Field of the Invention
The present invention relates to a controller, a control system and a control method for an engine system.
2. Description of Related Art
An internal combustion engine mounted on a vehicle or the like is known which includes a turbocharger and an exhaust gas recirculation (EGR) unit. The turbocharger includes a compressor disposed in an intake gas passage and a turbine disposed in an exhaust gas passage. The turbocharger performs supercharging using energy of exhaust gas. The EGR unit includes an EGR passage through which the exhaust gas passage and the intake gas passage communicate with each other. The EGR unit recirculates a part of the exhaust gas in the intake gas. As described in Japanese Patent Application Publication No. 2012-102617 (JP 2012-102617 A), an internal combustion engine is known in which the intake gas passage side of the EGR passage is connected to an upstream portion of the compressor in the intake gas passage.